import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        while(sc.hasNext()){
            int n=sc.nextInt();
            int m=2*n-1;
            int arr[][]=new int[n][m];
            for(int i=0;i<n;i++){
                for(int j=0;j<m;j++){
                    arr[i][j]=0;
                }
            }
            arr[0][0]=1;
            for(int i=1;i<n;i++){
                arr[i][0]=1;
                arr[i][2*i]=1;
                for(int j=1;j<2*i;j++){
                    if(j==1){
                        arr[i][j]=arr[i-1][j]+arr[i-1][j-1];
                    }else {
                        arr[i][j] = arr[i-1][j]+arr[i-1][j-1]+arr[i-1][j-2];
                    }

                }
            }
            int k=0;
            for(;k<m;k++){
                if(arr[n-1][k]%2==0){
                    System.out.println(k+1);
                    break;
                }
            }
            if(k==m){
                System.out.println(-1);
            }
        }
    }
}


